1. Field of the Invention
The present invention relates to a light emitting diode and a method for fabricating the same, and more particularly, to a light emitting diode capable of emitting light with a homogeneous color profile and a method for fabricating the same.
2. Description of the Related Art
FIG. 1 is a sectional view of a conventional light emitting diode emitting white light. Referring to FIG. 1, a blue-light emitting diode 2 is located inside a lead frame 1, with wires 3 connected to the top surface thereof via ohmic contact and to the lead frame 1 to supply electricity. The inner space of the lead frame 1 is filled with a phosphor 6 so that blue light emitted from the blue-light emitting diode 2 is converted to red or green light or and then to white light by being mixed up with the red or green light.
However, such a conventional blue-light emitting diode 2 cannot emit homogeneous white light profile and tends to emit light of wavelengths different from the wavelength of white light or conical light with a yellow or blue light ring.
Various solutions to this problem have been suggested. For example, according to a light emitting diode disposed in U.S. Pat. No. 5,813,753, as shown in FIG. 2, a light emitting diode 11 is provided in a cup-shaped header 12. A mirror 13 is formed on the inner wall of the header 12 to reflect light emitted from the light emitting diode 11. The inner space of the header 12 is filled with a transparent material 15 containing phosphor grains 14 dispersed around the light emitting diode 11. A glass plate 16 is placed on the top of the header 12 to prevent light which is not absorbed by the phosphor grains 14 from being emitted into the air. A low-wave pass (LWP) filter is further placed on the front side of the light emitting diode 11 to pass short-wavelength light more efficiently than long-wavelength light.
However, in manufacturing such conventional light emitting diodes, it is difficult to control the amount of phosphor grains that is necessary to emit light of desired wavelength bands. A transparent material containing phosphor grains should be deposited for individual light emitting diodes. Accordingly, a great chromatic difference between the separate light emitting diodes occurs, and the manufacturing time increases.
EP O 855 751 A2 discloses an organic/inorganic semiconductor light emitting diode emitting red light and blue light that is manufactured by appropriately doping a green phosphor layer. However, it is difficult to uniformly dope the phosphor layer to an appropriate ion concentration to obtain light of a uniform color profile.